Rectifying arc device



Jan. 15, 1929.

, 1,699,103 J. J. FITZ PATRICK ET AL RECTIFYING ARC DEVI CE Filed March 11, 1925 Im/enbors'? James J; F'itzpatricK, RalphT Cheeseman,

b k jf y Their/Attorney Patented Jan. 15, 1929.

UNITED STATES PATENT OFFICE.

JAMES J. IITZ PATRICK, OF MABBLEHEAD, AND RALPH '1. CHEESEMAN, OI LYNN, MASSACHUSETTS, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A. CORPORATION or NEW Yoax.

BECTIFYING anc DEVICE.

ancandescence and an anode which is maintained relatively cool. It'is the object of our invention to increase the efficiency and uniformity of this class of devices.

Hcretofore, it has been the practice to seal the electric terminals for the electrodes into opposite necks or arms of a bulb. This construction rendered it impracticable to space apart the electrodes an exactly predetermined distance and required separate -atta :hment'of the external current conductors to the terminals when the bulb is inserted in its outfit.

In accordance with our invention the cathode and the anode are sealed into a stem projecting into the neck of the bulb and are spaced apart a distance not materially greater than the arc gap between the electrodes. By using this construction the gap between the electrodes can be accurately gauged prior to sealing the stem into the bulb and thereby the best operating conditions can be secured. The size of the bulb can be decreased by this construction and contact members can be provided which are connected by a single operation, such as screwing the bulb into a socket similar to the insertion of an incandescent lam into its socket. The novel features of our invention are set forth with greater particularity by the appended claim.

The accompanying drawing shows in Fig. l a vertical sectional view of our improved rectifier bulb; Fig. 2 shows in perspective an outfit in which the bulb is mounted in a socket in suitable relation to a transformer and auxiliary devices, part of the wall being shown broken away; and Fig. 3 is a diagram of circuit connections.

Referrin to the drawing, the rectifier device as s own in Fig. 1 comprises a bulb 1 having a neck 2 in which is sealed 8. glass stem or press 3, and containing a gas at substantial pressure. The cathode leadingin. conductors 4, 5, andthe anode conductor 6 are sealed by fushion into this stem and extend side by side into the bulb. No discharge occurs between the cathode and anode conductors under normal operating conditions.

The cathode conductors 4, 5 are terminated by a filamentar spiral cathode 7, preferably consisting o tungsten. The conduct-or 6 is terminated by a disc-shaped anode 8 consisting of suitable conducting material, such as nickel, molybdnum, tungsten or graphite. The catho'de conductors 4, 5 are joined electricall to the members 9, 9 of a screw base and e anode conductor (5 is joined electrically to a metal ring 10 encircling the neck of the bulb just above the screw base.

In the manufacture of the bulb the operator first mounts the electrodes on the stem 3 and gauges the spacing between the cathode and the anode to a distance which has been found to give the desired operating characteristic.

These characteristics, such as starting The described form of rectifier bulb is well adapted for insertion into an outfit such as shown in Fig. 2. This outfit comprises a sheet metal container 11 having mounted in its base the core 12 of a transformer having windings 13, 14. Mounted upon the side wall of the container isa socket 15 (shown partly broken away) into which the rectifier bulb may be screwed as shown in Fig. 3. The members 16, 17 of the base are connected by the conductors 18, 19 to a section 14 of the secondary winding of the transformer whereby the cathode. is furnished with heating current. The ring 10 is connected by aspring contact 20 to the negative terminal 21 of the apparatus.

When a battery 22 is to be charged it is connected either to the positive terminals 23, 24 or 25, depending on the voltage desired. A resistance 26 is included in circuit with the positive tap or circuit 24 whereby the direct current voltage is reduced for chargin a battery of lower voltage. The high vo tage ta 25 contains an incandescent lam 27 w ich is mounted in a socket 28 afiixe to the outside wall of the con tainer. This relatively high voltage tap is adapted for charging high voltage storage batteries for radio outfits.

The sliding contact between the rin 10 and the spring pressed terminal 20 is a apted to carry relatively large currents without arcing difiiculties as it readily maintains itself in positive conducting relation.

What we claim as new and desire to secure by Letters Patent of the United States,

A rectifier comprising a glass bulb having a neck which terminates in a stem, a filamentary cathode and a coo crating anode positioned in said bulb, con uctors for the filament and anode sealed into said stem, a screw base secured to the stem and rovided with contacts which are connecte to the filament conductors, a metallic band-shaped member encircling said neck and spaced therefrom by insulating material and a connection between said member and the anode conductor.

In witness whereof, we have hereunto set our hands this ninth day of March, 1925. JAMES J. FITZ PATRICK. RALPH T. CHEESEMAN. 

